Automatic clutch control



Jan. 21, 1936. H. F. ELLIOTT 2,028,198

AUTOMATIC CLUTCH CONTROL Filed Feb. 23, 1932' Patented Jan. 21, 1936 UNITED STATES PATENT OFF-ICE 2,028,198 AUTOMATIC CLUTCH CONTROL Harold F. Elliott, Palo Alto, Calif. Application February 23, 1932, Serial No. 594,545

4 Claims. (o1. 192-.01)

This invention relates to automotive vehicles, and particularly to the clutch mechanism for controlling the connection of the propelling means to the transmission or wheels of the vehicle.

In the usual type of automotive vehicle, the propeller shaft is connected to the transmission by a clutch. This clutch is usually of the cone or disc type, in which the cooperating parts can be separated by depressing a clutch pedal. Such separation is desirable or necessary when shifting gears (that is, when varying the ratio of transmission from the engine to the propeller shaft), or for coasting. Such coasting has lately been referred to as free wheeling.

It has been proposed to provide a power mechanism for making it possible to release the clutch, as by the aid of a vacuum cylinder, so as to relieve the driver from the necessity of strongly urging the clutch pedal downward. This can be accomplished for example by a push button operating a valve in the vacuum line from the intake-manifold, which line leads to the operating cylinder. However, in such schemes it has been necessary to keep the button depressed.

It is one of the objects of my invention to make it possible to keep the power mechanism that-holds the clutch in released position, active for any desired period without the necessity of holding the button; and also to return the clutch to engaging position at will.

My invention possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of one embodiment of my invention. For this purpose I have shown a form in the drawing accompanying and forming part of the present specification. I shall now proceed to describe this form in detail, which illustrates the general principles of my invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of my invention is best defined by the appended claims.

Referring to the drawing:

Figure 1 is a diagram of the system, showing the engine only in outline; and

Fig. 2 is an enlarged detail view of the clutch pedal and its associated parts.

In Fig. 1 there is disclosed a gasoline engine I I having an intake manifold l2 in whicha suction is produced by the action of the engine pistons. The transmission of power to the vehicle is completed by a separable clutch device, such as l3. This clutch can be disengaged as for example by a downward thrust on a pedal [4. This pedal has a flat portion 35, which is arranged to Contact veniently be the intake manifold I2.

a boss 36 on crank I5, to urge it downwardly when pedal 14 is depressed. A link It connects crank IS with a shift fork H. The shift fork l I acts to move one of the clutch elements axially to disengaging position, whenever link I6 is moved 5 to the right 'as pedal [4 is depressed. Since this type of mechanism is all old and well known, further explanation is considered unnecessary.

Alternate means for operating the clutch I3 is shown, by the aid of a power mechanism. Thus 10 crank Hi can be actuated to clutch disengaging position by the aid of a vacuum cylinder [8 Operating, when under vacuum, to pull rod l9 pivoted to crank l5, toward the right. This movement rotates crank [5 to the clutchdisengaging 5 position.

The source of vacuum or suction can con- Thus a conduit 20 can lead from this manifold into the space of cylinder [8. The left hand side of the 20 cylinder I8 is of course vented to the atmosphere.

A slide valve 2| controls the passageway. in conduit 20. This valve can be opened as by link 22 and a lever 23. Thislever has a knob 24 which isarranged for convenient manual control, as by 5 the foot of the operator. Spring means 34 can be used to return the valve 2| to closed position when the button or knob 24 is released.

It is thus apparent that if the clutch I3 is to be disengaged, it can be alternatively accomplished 30 by pressing button 24 or pedal l4. However, in the present arrangement, there is shown a supplemental slide valve 25 for controlling the passageway in conduit 20, which normally closes this passageway. By the aid of a link mechanism 26, 35 the throttle control pedal or accelerator 21 is connected to this valve. When this pedal 21 is released for idling the motor or for slowing down, the pedal rocks upwardly and opens conduit 20. Thus cylinder l8 can be made active only under 40 engine idling conditions. When the accelerator pedal is thus released, button 24 can be used to disengage the clutch I3. Vents comprising slots 3'! and 38 are provided on the under side of slide valves 25 and 2|. These slots open the 4.5 lower section of conduit 20 to the atmosphere and. allow the clutch l3 to engage when valve 25 is moved to the left by pressing accelerator pedal 2 in. r

23, to hold it in clutch releasing position. This latch is shown in active holding position in both moved downwardly by the movement of pedal M, the latch is lifted by the aid of the cam surface 33. Then as lever 23 springs backto the position shown in dotted lines in Fig. 2, the pedal Hi can be released. Only a slight downward movement of pedal I4 is required to eifect this, and. it does not materially afiect the operation of the vehicle.

' The mode of. operation of the system can now.

be set forth. Under normal running conditions, without free wheeling, button 24 is raised, and valve 2| is closed, interrupting the passage I through conduit 20. Therefore, vacuum cylinder I8 is inactive, and the clutch I3 is solely under the control of pedal I4.

Now if free wheeling operation is desired, button 24 is depressed, and is held in the position of Fig. l by latch 28. Under such circumstances, the automobile can be propelled by depressing accelerator 21. This condition is shown in Fig. l. Theclutch I3 is still in engagement, since accelerator pedal 21 is depressed, and cylinder I3 is still inactive, valve interrupting the conduit 20.

However, as soon as pedal 2'! is released, clutch I3 is disengaged, because valve 25 opens conduit 20, and cylinder l8 becomes active. The car is now under free wheeling.

To place the clutch I3 again under the control of'pedal l4, it is merely necessary to depress pedal M slightly. This act causes pin 32 to release catch 28, and lever 23 is returned to a position where valve 2| interrupts conduit 20. The releasing operation of lever 23 is indicated in dotted lines in Fig. 2.

The mechanism including conduit 20, and cylinder I8 can be designated a free wheeling mechanism, and valves 2|, 25, and levers 24 and manual disengaging means is moved.

2. In a control mechanism for transmission of power from an internal combustion engine to a vehicle, said engine having an intake manifold,

a clutch, a suction operated device for operating the clutch, including a conduit to the manifold, as well as a manually controlled member for controlling the passageway through the conduit, a manually controlled pedal for alternatively manually disengaging the clutch, a latch for holding the passageway controlling member in position to hold the passageway open, and means whereby the latch is released when the pedal is given a slight clutch disengaging movement.

3. In an automotive vehicle having an engine, a transmission, a driving clutch between the engine and the transmission, a main clutch pedal for manual control of the driving clutch, a throttle for the engine, and auxiliary means for automatically operating the clutch in cooperation with the operation of the throttle, the combination of a member for holding said auxiliary means in condition for automatic clutch operation, andmeans whereby manual control of the clutch is restored when the main clutch pedal is at least partly depressed.

4. In an automobile having an engine, an accelerator pedal, a clutch, a clutch control member, and a mechanism for permitting the automobile to coast free of the engine when the accelerator pedal is released, an auxiliary control member for rendering said mechanism efiective, a latch for holding the mechanism in its efiective condition, and means actuated by the clutch control member for disengaging the latch.

HAROLD F. ELLIOTT. 

